The second instinct is to sit down and think about the man—a double-amputee and an Iraqi war veteran, I’m told—who several times a week can be viewed running around the Central Park reservoir. He laps most every jogger, in scorching heat, and causes all of us who come across him to want to be … better.

The third instinct is to smile and shake the head again over the news that Oscar Pistorius, a South African runner, this week became the first amputee to be named as a competitor in the Olympic Games. Pistorius, who has spent most of his 25 years without lower legs, will compete in London in the 400 meters (his favorite event) and the 1,600-meter relay, and will later compete in the Paralympic Games.

He’ll do so on the same pair of prosthetic, carbon-fiber limbs, or blades, known as the “Cheetah Flex-Foot” that once caused him to be handcuffed and detained at an Amsterdam airport, when police suspected him of being a terrorist. Every Olympian has a compelling back-story, but none have been this fascinating.

Born without both fibulas, the bone that runs from behind the knee to the ankle, Pistorius was 11 months old when his legs were amputated at mid-calf. Nevertheless his boyhood was spent participating in a whirl of sports at Pretoria schools—rugby union, water polo, tennis, wrestling—until a knee injury at age 16 forced him to give up the rough scrums of rugby and turn to running.

A year later he appeared in the Paralympic Games, got faster and faster on his prosthetic legs and was competing against able-bodied athletes by 2007. Critics began claiming his “Cheetahs” gave him an unfair advantage—they are said to weigh approximately half of a typical sprinter’s lower leg—and in early 2008 the International Association of Athletics Federations banned the blades from its events, notably the Olympics.

Concerned that the spring-like step in his stride provided him an unfair edge, the IAAF amended its rule to prohibit the use of “any technical device that incorporates springs, wheels or any other element that provides a user with an advantage over another athlete not using such a device.”

Pistorius appealed the decision, and soon the Court of Arbitration for sport ruled in his favor. He’s been defending his right to run on what he has joked as being “equal footing” ever since.

That alone must be exhausting, always pushing against arguments that are best debated by scientists and engineers. As a child making do with what he didn’t have, Pistorius surely never contemplated he’d ever be accused of having an “unfair advantage”—In what warped sci-fi parallel would that make sense?

But now here he stands, a man without legs soon to be flying around the track with a handful of the best quarter-milers on the planet. Think of the doors it will open, the imaginations that shall stir. Picture what might come if a double-leg amputee wins a medal, climbs the podium and defies all that we think we know about the human body and its supposed limitations.

Pistorius believes it his journey in life to educate people positively about those with disabilities. He’s fond of telling children that a giant shark bit off his legs, or that they fell off because he didn’t eat his green vegetables. He’s an ambassador for the Mineseeker Foundation, which supplies prosthetic limbs to the victims of landmines in Mozambique.

When his prosthetic legs caused alarms to blare at Schiphol airport in 2008, and traces of an explosive substance were discovered on his body, Pistorius was detained in a cell as a suspected terrorist.

“It wasn’t until later that I realized what had happened. I’d been clay pigeon shooting with a friend. Traces of dust from the shots must have got onto my legs,” Pistorius explained in his autobiography.

He’s used to the stares, the questions, but now that he’s earned the right to become the first amputee track athlete to compete at any Games, the most intractable ethical conundrum in recent sporting history will reach fever pitch. His nickname Blade Runner won’t always be considered clever.

Plenty of areas might still be gray, though the blades Pistorius uses haven’t changed since 2004. The technology has been around since 1996, tested and improved and approved over time. Meanwhile, Pistorius in the last few years has become lighter, stronger, after he was involved in a severe boating accident on the Vaal river in South Africa in 2009.

His jaw and two ribs were broken, his cheekbone crushed, and it took 172 stitches to piece back together his face. This adrenaline junky thought he was going to die. It made him change his life, give up junk food—pictures show him to be quite chunky four years ago—and limit the kamikaze moments on his Yamaha superbike. His beloved pet white tigers, Vesta and Valcan, have moved from his home to a nearby game reserve, where he can still play with them.

“I train harder than other guys, eat better, sleep better and wake up thinking about athletics,” Pistorius has said. “That’s probably why I’m a bit of an exception.”

Controversy still stalks him. A 2009 report in the Journal of Applied Physiology claimed that the crescent-shaped Cheetahs might—might—provide as much as a 10-second boost over 400 meters. And what if he runs any leg of the relay other than the first? It’s been suggested that the safety of other athletes could be jeopardized as they bunch inside for the final legs.

His spatial relationship with the ground is completely different than that of other runners. In some ways, he must work harder to make up for the loss of a natural running stride, but his shorter leg turnover time means less oxygen demand and, presumably, less strain on the heart. He can skip foot, ankle and calf work-outs, but the painful blistering and abrasions caused from the blades often disrupt his training regime.

“At the end of the day there are tens of thousands of people using the same prosthetics I use and there’s no-one running the same times,” he told the Daily Mail in March. “You’re always going to get people who have their opinions and offer their opinions, but they can’t explain things like that.”

And how would an able-bodied athlete feel if Pistorius beat him? Hopefully they’d all think like Great Britain’s Martyn Rooney, a sixth place finisher in the 400m in Beijing. Said Rooney recently: “I wouldn’t be too bothered. I’d be a lot angrier if, say, someone who had failed a drug test beat me. Oscar has not gone out of his way to cheat. This is his situation: he needs to run with those blades. He can modify things in ways that we can’t, but there’s things we can do that he can’t, so it balances out quite well. The athletes who complain are the ones who aren’t running fast enough.”

Another question: Now that Pistorius is competing in the Olympics, shouldn’t he give up his spot in the Paralympics so another athlete might fulfill a dream? If the South African Olympic committee selected Pistorius as part of the able-bodied team, should he still be considered disabled for the Paralympics?

At the moment, Pistorius says he’s extremely excited about the Paralympic Games, which begin in London 17 days after the Olympics end. He plans to defend his Paralympic titles in the 100 meters, 200 meters and 400 meters, along with being part of the South African team competing for a world record in the 4X100-meter relay.”

“Today is truly one of the proudest days of my life,” Pistorius said Wednesday after South African sports officials placed him on the nation’s Olympic team, a controversial decision considering he had met the Olympic qualifying standard in March but had fallen just short of the country’s stringent qualifying standards.

It was the right decision, no matter how many questions and grumps follow. It might force us to examine through a fresh lens how to push through limitations. It might even cause the world to stand up in unison and shout, “Bravo!”